Zhong Nanshan (Photo:VCG)

China's top respiratory diseases expert Zhong Nanshan said environment-to-human transmission has become a new pattern in the spread of COVID-19, and called on scientists to look for answers to this growing problem.

Zhong's comments came amid a slew of outbreaks in Chinese cities that were caused by contaminated outer packaging of imported cold-chain foods.

"Can humans get infected by the outer packaging of frozen products? How high will the virus concentration get when causing infection? How long can the virus survive? These new problems require us to discover the transmission patterns and come up with preventive measures," Zhong pointed out at an event Saturday.

Despite continuous outbreaks in Chinese cities caused by imported foods, the Global Times found that foreign media frequently criticized China's tightened measures on inspecting imported cold-chain foods for lacking scientific basis, even casting doubt on China's intentions in imposing such measures.

Earlier, the Chinese Center for Disease Control and Prevention (CDC) had detected and isolated living coronavirus in a positive sample from the outer packaging of imported frozen cod in Qingdao, East China's Shandong Province.

Zhong Nanshan made the assertion that COVID-19 could be transmitted between humans in the early stages of the epidemic in January.